1973: First Animal Gene Cloned

Stanford and UCSF researchers fused a segment of DNA containing a gene from the African clawed frog Xenopus with DNA from the bacterium E. coli and placed the resulting DNA back into an E. coli cell. There, the frog DNA was copied and the gene it contained directed the production of a specific frog protein. This was the first time an animal gene was cloned - that is, isolated and propagated like this.